A necessary consequence of the nature of neural transmission systems is that as change in the physical state of a time-varying event takes place, delays produce error between the instantaneous registered state and the external state. Another source of delay is the transmission of internal motor commands to muscles and the inertia of the musculoskeletal system. How does the central nervous system compensate for these pervasive delays? Although it has been argued that delay compensation occurs late in the motor planning stages, even the earliest visual processes, such as phototransduction, contribute significantly to delays. I argue that compensation is not an exclusive property of the motor system, but rather, is a pervasive feature of the central nervous system (CNS) organization. Although the motor planning system may contain a highly flexible compensation mechanism, accounting not just for delays but also variability in delays (e.g., those resulting from variations in luminance contrast, internal body temperature, muscle fatigue, etc.), visual mechanisms also contribute to compensation. Previous suggestions of this notion of "visual prediction" led to a lively debate producing re-examination of previous arguments, new analyses, and review of the experiments presented here. Understanding visual prediction will inform our theories of sensory processes and visual perception, and will impact our notion of visual awareness. "re-discovered" what he termed as the flash-lag effect and subsequently published a brief paper on it (in Nature, 1994). This paper provocatively introduced the notion of prediction in sensory pathways, giving rise both to active empirical research on the flash-lag phenomenon, and to a spirited debate regarding the existence and nature of visual prediction. Since then, Nijhawan has published multiple papers in the area of sensory prediction.Abstract: Speculation by Nijhawan that visual perceptual mechanisms compensate for neural delays has no basis in the physiological properties of neurons known to be involved in motion perception and visuomotor control. Behavioral and physiological evidence is consistent with delay compensation mediated primarily by motor systems. Perception-action as reciprocal, continuous, and prospectiveAbstract: From the perspective of ecological psychology, perception and action are not separate, linear, and mechanistic processes that refer to the immediate present. Rather, they are reciprocal and continuous and refer to the impending future. Therefore, from the perspective of ecological psychology, delays in perception and action are impossible, and delay compensation mechanisms are unnecessary.Abstract: Challenges to visual prediction as an organizing concept come from three main sources: (1) from observations arising from the results of experiments employing unpredictable motion, (2) from the assertions that motor processes compensate for all neural delays, and (3) from multiple interpretations specific to the flash-lag effect. One clarification that has emerged is that...

In Michotte's launching displays, while the launcher (object A) seems to move autonomously, the target (object B) seems to be displaced passively. However, the impression of A actively launching B does not persist beyond a certain distance identified as the “radius of action” of A over B. If the target keeps moving beyond the radius of action, it loses its passivity and seems to move autonomously. Here, we manipulated implied friction by drawing (or not) a surface upon which A and B are traveling, and by varying the inclination of this surface in screen- and earth-centered reference frames. Among 72 participants (n = 52 in Experiment 1; n = 20 in Experiment 2), we show that both physical embodiment of the event (looking straight ahead at a screen displaying the event on a vertical plane vs. looking downwards at the event displayed on a horizontal plane) and contextual information (objects moving along a depicted surface or in isolation) affect interpretation of the event and modulate the radius of action of the launcher. Using classical mechanics equations, we show that representational consistency of friction from radius of action responses emphasizes the embodied nature of frictional force in our cognitive architecture.